1. Field of the Invention
The invention generally relates to an electromagnetically driven valve. More specifically, the invention may be applied, for example, to a pivot-type electromagnetically driven valve for an internal combustion engine, which is operated by an elastic force and an electromagnetic force.
2. Description of the Related Art
U.S. Pat. No. 6,467,441 describes an example of an electromagnetically driven valve. In a conventional electromagnetically driven valve, a gap between a disc and an electromagnet is large, and an electromagnetic force is small on a central-axis side. Therefore, it is difficult to obtain a large initial driving force. Further, the amount of electric current needed in order to obtain a large initial driving force is large. This increases the amount of consumed electric power.
In view of the above, it is an object of the invention to provide an electromagnetically driven valve that can reduce the amount of consumed electric power and sill provide a sufficient driving force.